Fire-alarm system.



J. DONITZ.

FIRE ALARM SYSTEM. nrmounou nun no. as. 19m}.

91 6,280. Patented Mar; 23, 1909. I 2 SHEETS-SHEET 1.

J. DUNITZ. FIRE ALARM SYSTEM. APPLICATION Hum no. 2a. 1900.

91 6,280, Patented Mar. 23, 1909.

2 SHEETS-SHEET 2.

"III! nouns "an: cm. lnsumcron. u. c

UNITED STATES PATENT OFFICE.

JOHANNES DONITZ, OF LEIPZIG, GERMANY, ASSIGNOR TO THE FIRM OF OSCAR SOHOPPE, OF LEIPZIG, GERMANY.

FIRE-ALARM SYSTEM.

Specification of Letters Patent.

Patented March 23, 1909.

To all wi'zon'z it may concern:

Be it known that I, JOHANNES DoNrrz, a citizen of the Empire of Germany, residing at Leipzig, in the Empire of Germany, have invented a new and useful Fire-Alarm System, of which the following is a specification.

There are known fire alarm systems which are each divided into a number of sections, so that at the central station it may be possible to ascertain in which part of a building 3 or the like a dangerous increase of the temperature occurs. Hitherto it was For instance customary to insert in each section with constant current an annunciator drop, which on the current being broken by some thermostat is caused to drop. In such systems, however, frequently the necessity of connecting in multiple several batteries could not be avoided. Other fire alarm systems with constant current, in which all the thermostats are connected in series nith a battery and a subsidiary device such as a relay or the like, present the defect, that the switching device requires constant and special attention.

My invention relates to a lire alarm system, which combines the advantagesof the above two known kinds of systems and avoids their defects. The new system is divided into several sections, which normally form together a single circuit and therefore can be worked with a single battery. The arrangement of the several sections is such, that not only any section in which a thermostat in consequence of a dan crous increase of the temperature breaks the current can be at once made known to the central statiol'i, but also several sections in which tin-*rmostats break the circuit can be simultaneously made known. Thus the defects of the said two known kinds of fire alarm systems, viz. voluminous batteries for continuous current on the one hand, and constant and special. attention to the switching dcvirc or devices on the other hand are avoided.

I will now proceed to describe my invention with reference to the accoinpanying drawings, in which-- Figure 1 is a diagram of a lire alarm system, Fig. 2 is a vertical section, on an enlarged scale, through the line w-r in Fig. 1 and also through the same line in Fig. 3 and shows a switching device partly in section and partly in elevation, Fig. 3 is a vertical cross section through the line y-z in Fig.

r l i i 1 l similar parts throughout the several views.

In Fig. 1 the system is assumed to be divided into three sections I, II, III each of which comprises several thermostats F F of any known construction. In accordance therewith a gravity drop annunciator with three annunciator dro s A A and A and their electromagnets E and E is disposed at the central station. At the latter moreover two batteries B and C, a su itching device S, a switch D, an electric bell H, a cutout I, a relay'R, a galvanometer G and a series of pin contacts K are disposed. The one pole o the battery B is connected with the first section I by means of lines 1 and 2 and. the other pole of the. battery B with the last section III by means of the lines 12 and 13, the galvanometer G, the line 14, the electromagnet E of the rela R, the line 15, the st itch D, the contact piece 16 and the line 17. The thermostats F F in each of the sections I, II and III are connected in series by lines 3. .7. .11. and are each arran ed to break the circuit on the temperature ecoming dangerously high. The battery B is arranged to normally send a constant current through the circuit just described.

The switchin device S comprises a clockwork shown at igs. 2 and 3 and a sup orting disk 18 of insulating material both oi which may be secured on a suitable board 19 in any known manner. The clockwork comprises a spiral spring 20, which is fastened with its external end on a stud 21 and with. its internai end on a winding shaft 22, that projects with its square and 23 into a hole 24 of the disk 18 and can be Wound up in the direction of the arrow in Fig. I by means of a key as usual. The winding shaft 22 has fast on it a ratchet wheel 25 and loose a gear wheel 26, which latter carries a spring-pressed awl 27 for engaging in the ratchet whee 25. The gear wheel 26 is arranged to put into motion an esoapement 34 by means of a pinion 28, its shaft 30, a gear wheel 29, a inion 31, its shaft 32 and an esca ement-wlieel 33, these parts turning in the irections of the several arrows shown in Fig. 3. The escapement 34 is ri idly connected. with two arms 35 and 36, ofw ich the one 35 isprovided with a straight spring 37. The latter can engage with a stop 38 on the armature 39 of the relay R, see Fig. i. A helical spring 40 tends to detach the armature 39 from the core of the electromagnet E and to press it on a stop 41. However, as the battery B circulates a constant current through the circuit mentioned above. it will be seen, that the armature 39 is normally attracted by the electromagnet E and is pressed against the other stop 42, so that its stop 38 checks the eseape nent 34. The shaft 30 of the clockwork extends through the central opening of the disk 18 and has fastened on it a circular disk 36 of insulating material and a sup )orting sleeve 43. The disk 36 is provided with a cam 44, which serves for normally pressingthe elastic switch D on its contact piece 16 and thereby closing the circuit of the battery B. A helical s ring tends to detach the switch D from tlie contact piece 16 and thereby to break the said circuit. ()n the suiporting sleeve 43 are fastened and insulated therefrom and from each other two annular contact disks 46 and 47. on which two contact springs 48 and 49 respectively constantly bear. These contact springs 48 and 49 are supported on the disk 18 by means of two binding posts 50 and 51, which are connected with the battery C b lines 52 and 53. The contact disk 46 is e ectrically connected with a bent arm 54, which passes through the other contact disk t7 and is insulated therefrom. It carries a contact spring 55, which is arranged to slide over the disk 18 and a series of contact pieces .36, 56, 56 56*. 56". disposed in a circle around the center of the disk 18. The other contact disk 47 is electrically connected with a bent arm 57. which carries two contact springs 58 and 59. The free ends of the latter are in the same radial line as the free end of the contact spring and are arranged to slide over the disk 18 and two concentric series of contact pieces 60, 60*, till, 60", 61F and 61, 61'. til, 61*, 6F which are arranged in the same radial lines as the contact pieces 56, 56", 56, 56 The intermediary contact pieces 61, 61, 61, 61", 61 are made shorter than the contact pieces in the two other series and it will be understood that during the motion of the clockwork the two arms 54 and 57 are permitted to tum over the two binding posts 50 and .31 and that the two extern al contact springs 55 and will come in contact with the corresponding contact pieces 56 and 60 in either radial line earlier than the middle contact spring 59 with the respective contact piece 61. The several contact pieces 56, 61, (it) are each electrically connected with a binding post on the rear side of the disk 18, as is shown in Fig. 2. The one pole of the battery C. is connected with the cut-out l by a line 62 and the other pole with the electric bell H by a line 63,

while a line 64 connects the cutmut l with the electric bell H. The cut-out I comprises two arallel cont act springs 65 and 66. which can )0 brought into contact with each other by means of a bell-crank lever 67 that is normally held by the hooked end of the armat urc 39 of the relay R. Only on the electromagnet E becoming without current and on the armature 30 being detached by the helical spring 40 for releasing the clockwork will the bell-crank lever 57 be permitted to press the upper contact spring 65 on the lower one 66 for closing the circuit oi the battery C, so that the electric bcll ll will ring. The arm 36 on the cscapcment 34 of the clockwork can be actuated br oncs linger while overcoming the tension of the spring 37 for adjusting the two arms 54 and 57 with the three contact springs 55, 5S and 5%) with regard tothe disk 18.

lhe series ol plug contacts l\ is shown as com )rising four pieces k. Tc, Ir and k, which can he. at will electrically connected by means of plugs inserted in their recesses. The piece l." is connected on the one hand with the lines 1 and 2 by a line 65 and on the other hand with the binding post of the contact )iece 6t! on the disk 18 by lilies (it) and 70. he piece lr' is connected on the one hand with the two lines 4 and 6 by a line and on the other hand with the binding posts of the two contact pieces 6t) and 56 by lines 71, 72 and T3. The piece 11" is connected on the one hand with the two lines 8 and it) by a line i) and on the other hand with the binding; posts of the two contact pieces tit! and by lilies 74, 75 and 76. The last piece Ix connected on the one hand with the lines 12 and 13 by a line 77 and on the other hand with the binding post of the contact piece sin by lines 75. 79 and. 80.

The coil of the clectromagnet l5 connected on the one hand with the line 71. 72 by a line 81 and on the other hand with the binding post of the intermediate contact piece 61 by a line 8;. The coil of the second electromagnct E is connected on the one hand with the line 74. 75 by a line 82% and. on the other hand with the binding post of the second intermediary contiuzt piece (H by a line 84. The coil ol the third electroniagnet E is connected on the one hand with the line 78, 79 by a line 85 and on the other hand with the binding post of the third intermediary contact piece 61 by a line 86. In the drawing only three sections 1, l1 and ill of the circuit are shown for want of space, but it will be understood, that the number of these sections may be increased and. should be like the number of radial lines on the disk 18 in each of which three contact pieces so. (it) and 61 are disposed. in this case it is obvious, that the contact piece 56 in the last radial line on the disk 18 requires to be connected with the last piece Ir of the series of plug contacts K and that the contact piece 60 in the lit! ltltl liitl last radial line requires to be connected with g R will become without current and will re the contact piece 56 in the preceding radial line as well as with the last but one piece kol the series of plug contacts K.

The armatures a, a and a of the three electromagnets E, E and E are arranged to normally rest on stops 87, 87 and are provided with noses 88, 88, on which the arms I), b and b of the annunciator drops A, A and A bear for holding the latter 1n their vertical positions. Three bridging switches L, L and L are dis osed beneath the three electromagnets E, I14 and E and are'normally detached from their contact )ieces c, c and c by helical springs 89, 89. he first bridging switch L is connected with the line 69, 7 O by a line 90 and its contact piece c is connected with the line 72 and the second bridging switch L by lines 91 and 92. The second contact piece a is connected with the line and the third bridging switch l) by lines 93 and 94. nected with the line by a line 95. The arms I), b and b of the annunciator dropsA, A and A are severally arranged on being released by. the noses 88, 88 of the armatures a, a and (t to press the bridging switches L, L and L on their contact pieces 0, c and c respectively.

The fire alarm system operates as follows: Normally a constant current will he sent from the battery B through the lines 1 and 2, the thermostats F F and their connecting lines 3 in section I, the lines 4 and 6, the thermostats F F and their connectin lines 7 in section II, the lines 8 91K 10, the thermostats F F and their connectin lines 11 in section III, the lines 12 an 13, the galvanometer G, the line 14, the coil of the electromagnet E in the relay R, the line 15, the switch D, its contact piece 16 and the line 17 back to the battery B, so that the electromagnet E continues attracting its armature 39 to check the clockwork of the switching device S, while the galvanometer G will show that current of the proper amount is circulating. By means of a key the spiral spring 20 of the clockwork is wound up, so t at the shaft 30 with the arms 54 and 57 and the contact springs 55, 58 and 59 can make several revolutions. All the annunciator drops A, A and A will occupy their vertical posltions and thus remain invisible in their re spective casings as usual. The bell-crank lever 67 of the cut-out I is held in its normal position shown by the hooked end of the armature 39. This state of the system will continue, as long as everything is all right. Should at some place in the building or the like, say at T in section II in Fi 1, the temperature become dangerously liigh, the respective part 96 in the thermostat F will become distorted, as is indicated by the dotted line, and thus break the circuit of the battery B. Then the electromagnet E in the relay The third contact piece 0 is conlease its armature 39 with its stop 38 and thereby the bell-crank lever 67 and the clockwork by means of its spring 37. The bell-crank lever 67 will drop and press the u per Contact s )ring 65 on the lower one 66 o? the cut-out to close the circuit of the electric bell 11, so that the latter will ring to call the attention of the official at the central station. The clockwork will. be put in motion, so that the shaft 30 with the arms 54 and 57 and the contact springs 55, 5S and 59 will turn in the direction of the arrow in Fig. 1. The cam 44 on the disk 36 will release the switch D, so that the latter will be detached from its contact piece 16 by the helical siring 45 and no current can henceforth circu ate in the circuit of the batterv B. At the moment that the two external contact springs 55 and 58 come in contact with the first contact pieces 56 and 60 a current will pass from the battery C through the line 52. the binding post 50, the contact spring 49, the contact disk 46, the arm 54, the contact spring 55, the contact piece 56, the lines 73, 72 and 71, the plug contact piece is, the line 4, the thermostats F F and their connecting lines 3 .in section I, and the lincs 2 and 68, the plug contact piece k, the lines 69 and 70, the contact piece 60, the contact swing 58, the arm 57, the contact disk 47, t e contact spring 49, the binding post 51 and the line 33 back to the battery C. Thereby it is insured, that the current actually takes the prescribed path through the said circuit. Immediately afterward also the internal contact arm 59 will come in contact with the first contact )lOCG 61. so that also a current will pass rom the line 72 through the line 81, the coil of the electroma net E, the line 82, the contact piece 61 an the contact spring 59 to the arm 57, so the elcctromagnet E and the section 1 will be connected in multiple with the battery (7. Now that the resistance of the coil of the electromagnet E is made considerably larger than that of the section I, the consequence will be, that but a small art of the whole current will iass through t 10 coil of the electromagnet l so that the latter is unable to attract its armature a. T hcrcfore the battery C will not )roducc any visible effect. The shaft 30 with the arms 54 and 57 continuingto turn, the three contact springs 58 and 59 will leave the three first contact pieces 56, 60 and 61 and after a short while first the two external contact springs 55 and 58 will come in contact with the second contact )ieces 56 and 60". Now that the section .I is broken, of course no current can pass through the same. Directly afterward also the middle contact s )riug 59 will come in contact with the secom contact piece 61". Then a current will pass from the battery lOO i through the line 52, the binding post 50, the lac contact spring 48, the contact disk 46, the arm 5-1, the contact spring 55, the contact piece 56 the lines 76, 75 and 83, the coil of the second electromagnct E the line 84, the contact piece 61 the contact spring 59, the

spring 49. the binding post 51, and the line .33 back to the battery C. The electromagnct. E being thus energized Will attract its armature a and thereb release the arm I) and the annunciator drop A so that the latter will drop and apiear in the respective Window as usual and the arm 1: Will press the bridging switch L on its contact piece so as to establish an electrical connection between the two lines 72 and 75, in other Words to bridge over the section II. The official st'cillg the annunciator drop A will know, that it is the section ll, where danger is approaching or a tire may have broken out.

The shaft 30 with the arms 54 and 57 coir tinuing to turn. the thrce contact springs 55, 58 and will leave the three second contact pieces 56, (it) and (51 and afterward come in contact with the third contact pieces 56, (it) and 61, when the same series of occurrences will tilli place in the section III as described above with reference to the section I. At last before the completion of the revolution of the shaft the cam 44 on the disk 36' will depress the switch I) to close the (i1- cuit of the hatter B, so that the current will now pass from the battery B through the lilies i and J, the thermostats F I and their connecting lines I; in section I, the lines 4 and 5, the plug contact piece 1' the lines 71. T2 and 92, the bridging switch U, the contact piece c". the lines 93, and 74, the plug conta t piece 1 the lines 9 and It], the thermostat F F and their connecting lines It .in section III. the lines 12 and 13, the galranomctcr G. the line 14, the coil of the clcctroinagnet W in the relay R, the line 15, the switch l). the contact new 16, and the line 17 back to the battery t. Thus the whole system with the exception of the section ll wiil be again in working order without the switching device S requiring any special attention. The place 'l in section ll can be meanwhile cxannncd and the danger can be removed or the tire extinguished, after which the respective thermostat F will resume its normal position. so that at the central station the annunciator drop A." can be returned to its vertical position. wherelrv the bridging switch ll" will be detached from its contact piece in other words the section it will be reinserted in the system. Of course the oflicial is at liberty to break the circuit of the electric bell ii by turning off the bellcrank lever ($7. after his attention hasheen ('tllliil.

seen. that the several sections of the system are examined one after the other by means I of the switching device 8 to ascertain the I section, in which a danger or fire may be, and i that the testing current from the battery C is sent first through any section and directly 4 afterward through the clectromagnet of the arm 57, the contact disk 47, the contact appertaining annunciator drop to make sure, that the respective section is actually broken.

l It also evident. that in several sections danger may occur at the same time and that these sections can be ascertained in the manner described above during a singie revolution of the shaft 30 with the arms 54 and 57 and the three contact springs 55, 58 and 59.

other section, in which some thermostat F is actuated, can be made known at the central station in the same manner as described above, the clockwouk being start-ed and the shaft 30 caused to make one revolution.

If necessary a plug may be inserted between any two pieces of the series of plug; contacts K for bridging over the respective section, so that repairs or the like may be made in the same without disturbing or rendering ineffective the whole system.

The fire alarm system. described may be varied in many respects without departing from the spirit of my invention.

l claim:

1. In an alarm system, the combination with a normally closed circuit divided into a plurality of sections of which one is within the central station, of pluralities of thermo stats in the several outer sections of said circuit and each thermostat being adapted to break the circuit, i'iormally open primary innor circuits connected with the division points of said circuit and adapted on being closed to send currents through the corres onding outer sections of said circuit, normally open secondary inner circuits shunted to said primary inner circuits and adapted to severally receive the current on the respective outer section of the circuit being: broken, announcing devices in said secondary inner circuits, means controlled by said announcin devices for bridging the several outer sections of said circuit, a relay in the inner section of said circuit, and means controlled It is likewise obvious, that afterward any I From the above explanations it will be by said relay for consecutively closing for a. moment the several )rimary and secondarv inner circuits on sairl circuits being opened.

2. In an alarm system, the combination with a normally closed circuit divided into a plurality of sections of which one is within the central station, of pluralitics of thermostats in the several outer sections of said circuit and each thermostat being adapted to break the circuit, normally open primary inner circuits connected with the division points of said circuit and adapted on being ciosed to send currents through the corresponding outer sections of said circuit, normally open secondary inner circuits shunted to said primary inner circuits and adapted to severally receive the current on the re- 1 spective outer section of the circuit being broken, announcing devices in said secondary inner circuits, means controlled by said announcing devices for bridging the several outer sections of said circuit, a relay in the i inner section of said circuit, means controlled by said relay for consecutively closing for a moment the several primary and secondary inner circuits on said circuit being opened, the closure of each primary inner circuit preceding that of the secondary inner circuit, and means for closing said circuit after the last primary and secondary inner circuits have been reopened.

3. In an. alarm system, the combination with a normally closed circuit divided into a plurality of sections of which one is within the central station, of pluralities of therinol stats in the several outer sections of said circuit and each thermostat being adapted to l break the circuit, normally open. primary inner circuits connected with the division points of said circuit and adapted on being closed to send currents throu h the corresponding outer sections of sair circuit, normally open secondary inner circuits shunted to said primal inner circuits and including electromagnets which can be energized only if the corresponding outer sections of said circuit are severall r broken, announcing devices controlled y said electromagnets, means controlled by said announcing devices for bridging the several outer sections of said circuit, a relay in the inner section of said circuit, a source of electricity, means controlled by said relay for consecutively closing for a moment the several primary and seeondary inner circuits while connecting them i with said source of electricity, the closure of 1 each primary inner circuit preceding that of the seconda inner circuit, and means for ciosin said circuit after the last primary and secondary inner cirwuits have reopened.

4. In an alarm system, the combination with a normally closed circuit divided into a plurality of sections of which one is within the central station, of pluralities of thermostats in the several outer sections of said circuit and each thermostat being adapted to break the circuit, normally open primary inner circuits connected with the division points of said circuit and adapted on being closed to send currents through the corresponding outer sections of said circuit, normally open secondary inner circuits shunted to said primary inner circuits and inclosing elcctromagnets which can be energized only if the corresponding outer sections of said circuit are severall broken, announcing devices controlled iy said cleetromagnets, means controlled by said announcing devices for bridging the several outer sections of said circuit, a relay in the inner section of said circuit, a source of electricity, a clockwork controlled by said relay to move on said circuit being broken, means driven by said clockwork for consecutively closing for a moment the several primary and secondary inner circuits While connecting them with said source of electricity, the closure of each primary inner circuit preceding that of the secondary inner circuit, and a switch controlled by said clockwork for closing said circuit after the last primary and secondary inner circuits have been reo ened.

JOHANL PIS DONIT'J.

Witnesses:

RUDOLPH Fnroxn, SOUTHARD P. WARNER. 

